Printing head for ink jet printer

Abstract

A printing head for an ink jet printer in which a multiplicity of channels are formed, preferably in one plate of the head. Each of the channels communicates with a capillary tube that opens into a boundary surface of the plate. The arrangement of the channels is such that the head can be of a smaller size than other constructions, and the openings of the capillary tubes can be located closer to one another.

What is claimed is: 
     
       1. Printing head for an ink jet printer comprising a first plate having spaced channels in one surface of said first plate, a separate plate having a pumping chamber for each of said channels and means for pumping fluid in each of said chambers, a plurality of capillary tubes each opening into another surface of said first plate, means connecting one end of each of said channels to a respective one capillary tube, one end of each of said capillary tubes forming an orifice for exiting the drops of printing fluid, each of said capillary tubes tapering in the direction from said channels to the opening of said tube and lying substantially in a straight line relative to a respective channel, and each of said capillary tubes opening into a surface of said first plate which is substantially perpendicular to the large surfaces of said first plate. 
     
     
       2. Printing head for an ink jet printer as claimed in claim 1, wherein each of said connecting means comprises a tapering part extending toward the capillary tube and forms a uniform transition into the latter. 
     
     
       3. Printing head for an ink jet printer as claimed in claim 1, wherein the angle of connection of each capillary tube to a corresponding channel is the same for all capillary tubes. 
     
     
       4. Printing head for an ink jet printer as claimed in claim 1 wherein said separate plate is provided with a recess and said first plate is inserted in said recess, said separate plate being provided with a plurality of channels corresponding to said spaced channels of the first plate which operatively connect each respective channel of said first plate to a corresponding pumping chamber. 
     
     
       5. Printing head for an ink jet printer as claimed in claim 1, wherein said channels are located in the opposite large surfaces of said plate, and said means connecting said capillary tubes to said channels wherein there are alternate connections from said capillary tubes to a channel on one large surface of said plate and to the other large surface of said plate.